Method and computer program product for controlling the control effectors of an aerodynamic vehicle

ABSTRACT

A method and computer program product are provided for controlling the control effectors of an aerodynamic vehicle including, for example, the respective positions of nozzles and aerodynamic surfaces, to affect a desired change in the time rate of change of the system state vector. The method initially determines differences between anticipated changes in the states of the aerodynamic vehicle based upon the current state of each control effector, and desired state changes. These differences may be weighted based upon a predetermined criteria, such as the importance of the respective states and/or the weight to be attributed to outliers. The differences between the anticipated and desired state changes are converted to the corresponding rates of change of the control effectors. Control signals are then issued to the control effectors to affect the desired change in the time rate of change of the system state vector.

FIELD OF THE INVENTION

The present invention relates generally to a method of controlling thecontrol effectors of an aerodynamic vehicle and, more particularly, toan integrated method for controlling the control effectors of anaerodynamic vehicle, including the aerodynamic surfaces, thrustvariations and nozzle vectoring, in order to efficiently cause a desiredchange in the time rate of change of the system state vector of theaerodynamic vehicle during various stages of flight.

BACKGROUND OF THE INVENTION

During flight, the control of aerodynamic vehicles, such as aircraft, isprincipally accomplished via a variety of flight control effectors.These flight control effectors include aerodynamic controls such as therudder, elevators, ailerons, speed brakes, engine thrust variations,nozzle vectoring and the like. By altering the various flight controleffectors, the system state vector that defines the current state of theaerodynamic vehicle can be changed. In this regard, the system statevector of an aerodynamic vehicle in flight typically defines a pluralityof current vehicle states such as the angle of attack, the angle of sideslip, the air speed, the vehicle attitude and the like.

Historically, the flight control effectors were directly linked tovarious input devices operated by the pilot. For example, flight controleffectors have been linked via cabling to the throttle levers and thecontrol column or stick. More recently, the flight control effectorshave been driven by a flight control computer which, in turn, receivesinputs from the various input devices operated by the pilot. Byappropriately adjusting the input devices, a pilot may thereforecontrollably alter the time rate of change of the current system statevector of the aerodynamic vehicle.

Unfortunately, flight control effectors may occasionally fail, therebyadversely affecting the ability of conventional control systems tomaintain the dynamic stability and performance of the aerodynamicvehicle. In order to accommodate failures of one or more of the flightcontrol effectors, control effectors failure detection and flightcontrol reconfiguration systems have been developed. These systemstypically remove the flight control effectors that has been identifiedas inoperable from the control system. These systems are thereforedesigned to detect the failure of one or more flight control effectorsand to alter the control logic associated with one or more of the flightcontrol effectors that remain operable in an attempt to produce thedesired change in the time rate of change of the current system statevector of an aerodynamic vehicle requested by the pilot. These failuredetection and flight control reconfiguration systems are highly complex.As such, the proper operation of these systems is difficult to verify.Moreover, these systems introduce a risk that a flight control effectorthat is actually functioning properly may be falsely identified ashaving failed and thereafter removed from the control system, therebypotentially and unnecessarily rendering the control system lesseffective.

Additionally, the control effectors of an aerodynamic vehicle generallyhave some limitations on their performance. In this regard, the rate ofchange accommodated by most control effectors is generally limited to arange bounded by upper and lower limits. By way of example, foraircraft, such as direct lift aircraft, that permit nozzle vectoring,the actual position which the nozzles may assume is typically limited towithin upper and lower limits. Unfortunately, conventional controlsystems do not accommodate limitations in the range of settings and rateof change of the control effectors. As such, conventional controlsystems may attempt to alter a control effector in a manner that exceedsits limitations. Since the control effector will be unable to make thedesired change, the control system may correspondingly fail to producethe desired change in the time rate of change of the system state vectorof the aircraft.

In addition to the aerodynamic surfaces commonly utilized to control theflight of an aerodynamic vehicle, aircraft has been developed that canprovide additional control by means of thrust variations and/or thrustor nozzle vectoring. For example, some multi-engine aircraft permit theplurality of engines to be driven differently so as to generatedifferent levels of thrust which, in turn, can serve to assist in thecontrolled flight of the aircraft. As another example, vectoring nozzlesthat may be commanded to assume any of a range of positions andbi-directional nozzles that direct the exhaust in one of two directionshave been developed. By controllably directing at least a portion of theengine exhaust in different directions, vectoring nozzles, which shallhereafter also generally include bi-directional nozzles, can also assistin the controlled flight of the aircraft.

While various control systems have been developed to control the flightcontrol effectors during flight, these control systems generally do notintegrate the control provided by aerodynamic surfaces during flightwith the control needed in instances in which the aircraft has no, or anegligible, velocity such that the aerodynamic control surfaces, such asthe rudder, elevators, ailerons or the like, do not significantlycontribute, if at all, to the lift and attitude control of the aircraft.In this regard, direct lift aircraft have been and are being developed.Direct lift aircraft have control effectors, such as vectoring nozzlesor bi-directional nozzles, that can direct the engine exhaust indifferent directions to provide lift and attitude control of theaircraft. By appropriately positioning the nozzles, a direct liftaircraft can takeoff and land in a substantially vertical manner. Assuch, during takeoff and landing, the aerodynamic control surfaces donot significantly contribute to the lift and the attitude control of thedirect lift aircraft. Instead, the lift and attitude control areprincipally provided and controlled by any thrust variations provided bythe engines and the vectoring of the associated nozzles.

In order to control the lift and attitude of an aircraft during avertical takeoff or landing, control systems have been developed tocontrol the engines and the associated nozzles. For example, one controlsystem employs an optimization algorithm, termed an L1 optimizationalgorithm. While generally effective, this optimization algorithmsuffers from several deficiencies. In this regard, the optimizationalgorithm is computationally complex, thereby requiring substantialcomputing resources and being difficult and costly to expand or scale toaccommodate more sophisticated control schemes, such as the controlscheme necessary to control vectoring nozzles as opposed to simplerbi-directional nozzles. The computational complexity of the optimizationalgorithm may also cause the solution to be approximated in instances inwhich the optimization algorithm cannot arrive at an exact solutionwithin the time frame required to maintain stability of the aircraft. Inaddition, the optimization algorithm may not converge in all situations.In instances in which the optimization algorithm may not converge, theprior solution, i.e., the solution from a prior iteration of theoptimization algorithm, would continue to be utilized, thereby resultingin a sub-optimal solution.

As such, it would be desirable to provide an improved control systemthat effectively integrates the various control effectors including theaerodynamic surfaces and the thrust variations and nozzle vectoring soas comprehensively control the aerodynamic vehicle during differentstages of flight, including for example, the vertical takeoff andlanding of a direct lift aircraft during which thrust variations andnozzle vectoring dominate the control scheme as well as in flight duringwhich the aerodynamic surfaces provide a greater measure of control. Inaddition, it would be desirable to develop a method of controlling thecontrol effectors of an aerodynamic vehicle, such as a direct liftaircraft, which provides increased flexibility with respect to theremoval or inclusion of a flight control effector that may have failed.In addition, it would be advantageous to provide a method forcontrolling the control effectors of an aerodynamic vehicle, including adirect lift aircraft, in a manner that recognizes and accommodateslimitations in the settings and rate of change of at least some of thecontrol effectors.

SUMMARY OF THE INVENTION

An improved method and computer program product are therefore providedfor controlling the plurality of control effectors of an aerodynamicvehicle in order to efficiently bring about a desired change in the timerate of change of the system state vector of the aerodynamic vehicle.Advantageously, the method and computer program product provide anintegrated control scheme for controlling thrust variations and nozzlevectoring, as well as various aerodynamic surfaces throughout all phasesof flight including takeoff, flight and landing. By integrating thecontrol of thrust variations and nozzle vectoring with the control ofaerodynamic surfaces, the method and computer program product can alsoprovide control during vertical takeoff and landing scenarios.

The method and computer program product of one aspect of the presentinvention permits the control of the control effectors to be tailoredbased upon predetermined criteria, such as the relative importance ofthe respective states of the aerodynamic vehicle and/or the weighting tobe given to any outlier measurements. According to another aspect, themethod and computer program product control the plurality of controleffectors while recognizing limitations upon the permissible changes toat least one control effector, such as limitations upon the rate ofchange or the range of positions of at least one control effector. Assuch, the method and computer program product of the present inventionaddress the shortcomings of conventional control systems and efficientlycommand the control effectors so as to alter the time rate of change ofthe system state vector of the aerodynamic vehicle in a desired manner.

The method and computer program product control the control effectors ofan aerodynamic vehicle by initially determining the current commandedstate of the plurality of control effectors including, for example, thecurrent commanded position of each nozzle, the current commanded levelof thrust for each engine and the current commanded position of at leastone aerodynamic surface. The method and computer program product thendetermine the differences between anticipated changes in the pluralityof states of the aerodynamic vehicle based upon the current state ofeach control effector and the current flight conditions, and desiredchanges in the plurality of states of the aerodynamic vehicle. In orderto determine the differences between the anticipated and desired changesin the plurality of state rates of the aerodynamic vehicle, the dotproduct of a vector representing the current commanded state of eachcontrol effector and a matrix representing changes in the plurality ofstates of the aerodynamic vehicle in response to changes in the controleffectors at the current flight conditions is initially determined. Inthis regard, the matrix includes a plurality of terms, each of whichrepresents the anticipated change in a respective state rate of theaerodynamic vehicle in response to the change of a respective controleffector at the current flight conditions. By considering the effect ofchanges in a control effector at the current flight conditions, themethod and computer program product can rely upon the control providedby thrust variations and nozzle vectoring more heavily during verticaltakeoff and landing and upon the control provided by aerodynamicsurfaces more heavily once in flight, thereby providing an integratedand robust control scheme. In order to determine the difference betweenthe anticipated and desired changes in the plurality of states of theaerodynamic vehicle, the vector difference between the dot product and avector representing the desired change in the plurality of states of theaerodynamic vehicle is obtained in one embodiment.

According to one aspect of the present invention, the differencesbetween the anticipated and desired changes in the plurality of statesof the aerodynamic vehicle are then weighted based upon a predeterminedcriteria. In this regard, the differences may be weighted based upon therelative importance of the respective states of the aerodynamic vehicle,thereby permitting those states which are believed to be of greaterimportance to be assigned a correspondingly greater weight. As a resultof this greater weight, the method and computer program product of thisaspect of the present invention will control the control effectors so asto more quickly alter these states than other states having lowerweights assigned thereto. In addition or in the alternate, thedifferences may be nonlinearly weighted by a predefined penalty basedupon the emphasis to be placed upon outliers, i.e., relatively largedifferences between the anticipated and desired changes in the pluralityof states of the aerodynamic vehicle. A predefined penalty may also beutilized to emphasize the importance of certain relationships, such asmaintaining area match for each engine, with relatively large penaltiesbeing assigned to variations from the desired relationship.

Based upon the weighted differences between the anticipated and desiredchanges in the plurality of states of the aerodynamic vehicle, themethod and computer program product may determine a second dot productof the weighted vector difference and a transpose of the matrixrepresenting changes in the state rates of the aerodynamic vehicle inresponse to changes in the plurality of control effectors. The seconddot product therefore represents the changes in the control effectorsrequired to affect the desired changes in the plurality of states of theaerodynamic vehicle, given the anticipated changes in the plurality ofstates. As such, the weightings assigned to the respective states of theaerodynamic vehicle will correspondingly effect changes in the desiredstate of the control effectors. By utilizing the transpose of the matrixrepresenting changes in the state rates of the aerodynamic vehicle inresponse to changes in the control effectors, the method and computerprogram product effectively cause the control effectors that will havethe greatest impact upon effecting the desired change to be adjusted toa greater degree than the control effectors that will have less impactupon effecting the desired change, thereby improving the efficiency ofthe control scheme. The second dot product may also be weighted by again matrix, one term of which is associated with each control effectorin order to appropriately weight the relative contributions of thecontrol effectors.

According to another advantageous aspect of the present invention, themethod and computer program product may also limit the permissiblechanges of at least one of the control effectors. In this regard, thepermissible rate of change of one or more of the control effectors maybe limited. Similarly, the position of one or more of the controleffectors may also be limited to within a predefined range. As such, themethod and computer program product of the present invention effectivelyrecognize and accommodate limitations of the control effectors, therebypreventing any attempts to drive the control effectors beyond theirpredefined limitations.

The method and computer program product then issue control signals tothe plurality of control effectors so as to implement at least a portionof the desired change in the time rate of change of the system statevector of the aerodynamic vehicle. In those aspects of the presentinvention in which the differences between the anticipated and desiredchanges in the plurality of states of the aerodynamic vehicle areweighted, the control signals are at least partially based upon theweighted differences. More particularly, in those embodiments in whichthe second dot product of the weighted vector difference and thetranspose of the matrix representing changes in the system state vectorof the aerodynamic vehicle in response to the changes in the pluralityof control effectors is determined, the control signals are at leastpartially based upon the second dot product. Moreover, the controlsignals may be more directly weighted by the gain matrix. Additionally,in those aspects of the present invention in which the permissiblechanges of at least one of the control effectors is limited, the controlsignals issued to the control effectors are subject to the limitationsin the permissible changes of one or more of the control effectors.Thus, at least a portion of the desired change in the plurality ofstates of the aerodynamic vehicle may be implemented without exceedingthe permissible changes of the control effectors.

Thus, the method and computer program product of the present inventionprovide an improved technique for efficiently controlling the controleffectors of an aerodynamic vehicle in order to effect the desiredchange in the time rate of change of the system state vector of theaerodynamic vehicle. Advantageously, the method and computer programproduct provide an integrated control scheme for controlling thrustvariations and nozzle vectoring, as well as various aerodynamic surfacesthroughout all phases of flight including takeoff, flight and landing.According to one aspect of the present invention, the control of thecontrol effectors may be influenced by weighting based upon apredetermined criteria, thereby permitting the control system to be moreindividually tailored and efficiently implemented. According to anotheraspect of the present invention, the permissible changes of one or moreof the control effectors may be limited such that the desired change inthe time rate of change of the system state vector of the aerodynamicvehicle may be affected without attempting to exceed the permissiblechanges of at one or more of the control effectors.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus described the invention in general terms, reference will nowbe made to the accompanying drawings, which are not necessarily drawn toscale, and wherein:

FIG. 1 is a block diagram illustrating the operations performed by themethod and computer program product of one embodiment of the presentinvention;

FIG. 2 is a graph representing the affect attributable to the impositionof different predefined penalties; and

FIG. 3 is an expanded view of the graph of FIG. 2 illustrating theaffect of the imposition of different predefined penalties.

DETAILED DESCRIPTION OF THE INVENTION

The present invention now will be described more fully hereinafter withreference to the accompanying drawings, in which preferred embodimentsof the invention are shown. This invention may, however, be embodied inmany different forms and should not be construed as limited to theembodiments set forth herein; rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. Likenumbers refer to like elements throughout.

A method and a corresponding computer program product are provided forcontrolling the plurality of control effectors of an aerodynamicvehicle, such as an aircraft, including, for example, a direct liftaircraft capable of vertical takeoff and landing. As known to thoseskilled in the art, aerodynamic vehicles have a wide variety of controleffectors with the type and number of control effectors depending uponthe type and model of the aerodynamic vehicle. By way of example,typical control effectors include aerodynamic surfaces, such as therudder, elevators and ailerons. Other control effectors include speedbrakes, engine thrust variations and nozzle vectoring including thecontrol of bi-directional nozzles. As will be understood by thoseskilled in the art, nozzle vectoring generally includes the positioningof the main lift nozzle and, in some embodiments, the positioning of thenozzles associated with one or more attitude control effectors.

As described below, the control method of the present inventionintegrates the control of these various control effectors, including theaerodynamic surfaces, thrust variations and nozzle vectoring, to permitimproved control over all phases of flight. Moreover, the control methodadvantageously utilizes the various types of control effectorsdifferently during different stages of flight based, at least in apart,upon the effect occasioned by changes in the various control effectorsat the current flight conditions. For a direct lift aircraft, forexample, the control effectors that are principally utilized duringvertical takeoff and landing are thrust variations provided by eachengine and the associated nozzle positions, i.e., nozzle vectoring, butdo not include the aerodynamic surfaces since the aerodynamic surfacesprovide very little, if any, control since the aerodynamic vehicle hasno forward velocity. Conversely, during wingborne flight, the controlmethod relies more heavily upon the aerodynamic surfaces and much lessheavily upon thrust variations and nozzle vectoring in order toefficiently control the aerodynamic vehicle.

As shown in FIG. 1 and described hereinafter, the control method may beimplemented in the discrete domain utilizing digital signals.Alternatively, the control method may be implemented in the continuousdomain utilizing analog signals if so desired. Regardless of the domainin which the control method is implemented, the control method depictedin FIG. 1 is automated and is generally implemented by means of acomputer, such as a flight control computer or the like. As such, thecontrol method is typically embodied in a computer program product whichdirects the flight control computer to issue appropriate commands to theplurality of control effectors in order to control the aerodynamicvehicle as desired.

As shown, the current commands {overscore (δ)} issued to the controleffectors are monitored. The current commands {overscore (δ)} define thecurrent state to which each control effector has been commanded. Forexample, the commands associated with an aerodynamic surface such as arudder, elevator or aileron define the position to which the respectiveaerodynamic surface is currently being directed to assume. Similarly,commands may be issued to the respective engines to define the thrust tobe generated and to the nozzles to define the position that the nozzlesshould assume. Typically, the current commands are represented by avector {overscore (δ)} which includes a term defining the state to whicheach respective control effector is currently commanded.

Based upon the current control effector commands {overscore (δ)}, theanticipated changes in the plurality of states of the aerodynamicvehicle are determined. In this regard, an aerodynamic vehicle that isin flight has a number of states {overscore (X)}, including the angle ofattack, the angle of side slip, the air speed, the vehicle attitude, thelift, the altitude and the like. In addition, the states of anaerodynamic vehicle that are considered by the control method may alsoinclude a plurality of engine parameters, such as temperature, pressure,total area and the like. As known to those skilled in the art, thestates of an aerodynamic vehicle may vary somewhat depending upon thetype and model of the aerodynamic vehicle, but are well defined for arespective type and model of aerodynamic vehicle.

In order to determine the anticipated changes in the system rate ofchange of the state vector {overscore (x)} of the aerodynamic vehiclebased upon the current commands {overscore (δ)}, a matrix$\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack$

may be defined that represents changes in the rate of change of therespective states (hereinafter termed the state rates) of theaerodynamic vehicle in response to changes in the plurality of controleffectors. See block 10 of FIG. 1. The matrix includes a plurality ofterms with each term representing the change in a respective state rateof the aerodynamic vehicle in response to the change of a respectivecontrol effector. As such, the matrix represents the manner in which theaerodynamic vehicle is anticipated to respond to changes in the controleffectors. Typically, the matrix is constructed to have a plurality ofrows and a plurality of columns. Each column generally includes aplurality of terms, each of which defines the anticipated change in arespective state rate of the aerodynamic vehicle in response to thechange in the same control effector. Thus, each column of the matrixrepresents the anticipated changes in the state rates of the aerodynamicvehicle due to a change of a respective control effector.

The matrix$\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack$

may be constructed by a variety of techniques. In one technique, thematrix is constructed as a result of numerical calculations. In thistechnique, the current states of the aerodynamic vehicle and the currentsettings of the control effectors are provided. Based upon the currentstates of the aerodynamic vehicle and the current settings of thecontrol effectors, the resulting forces and torques acting upon theaerodynamic vehicle are determined. By factoring in the mass and inertiaof the aerodynamic vehicle, the state rates may be determined.

In order to determine the resulting forces and torques acting upon theaerodynamic vehicle, the aerodynamic coefficients for the current flightcondition, as defined by the current states {overscore (x)} of theaerodynamic vehicle, are determined. As known to those skilled in theart, aerodynamic databases are available for most aerodynamic vehiclesthat define the various aerodynamic coefficients based upon the currentstates of the aerodynamic vehicle. The aerodynamic coefficients of anaerodynamic vehicle may vary based upon the type and model of theaerodynamic vehicle, but typically include coefficients such as lift,drag, pitching moment, side force, rolling moment, yawing moment and thelike. While the aerodynamic coefficients may vary based upon the typeand model of the aerodynamic vehicle, the aerodynamic coefficients for aparticular type and model of aerodynamic vehicle will be well definedand known to those skilled in the art.

The resulting forces and torques upon the aerodynamic vehicle can thenbe determined based upon the aerodynamic coefficients by means of forcebuildup equations, also known to those skilled in the art. In thisregard, the force buildup equations will also generally vary dependingupon the type and model of aerodynamic vehicle. However, for aparticular type and model of aerodynamic vehicle, the force buildupequations are well established and known to those skilled in the art. Inaddition to the aerodynamic coefficients, force buildup equationsgenerally take into account the current dynamic pressure as well as anumber of other parameters, such as the mass, inertia, span, referencearea and the like, which are well known to those skilled in the art. Thedynamic pressure is based upon the square of the velocity such that theforce buildup equations effectively take into account the current flightconditions.

The anticipated changes in the state rates of the aerodynamic vehicleare then determined based upon finite differences. In this regard, onecontrol effector is considered to have varied slightly, such as 1% orless, from its current state and the process of determining theresulting forces and torques acting upon the aerodynamic vehicle isrepeated, albeit with the state of one control effector having beenvaried somewhat. The resulting change in the forces and torques actingupon the aerodynamic vehicle following the slight variation of onecontrol effector are then determined. By factoring out the mass andinertia of the aerodynamic vehicle from the force buildup equationsrepresentative of the changes in the forces and torques occasioned by aslight variation in one control effectors, the change in each state rateof the aerodynamic vehicle attributable to the change in the respectivecontrol effector may be determined, thereby defining one column in theresulting matrix$\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack.$

The foregoing process of slightly varying a respective control effectorand determining the resulting change in forces and torques acting uponthe aerodynamic vehicle and, correspondingly, the resulting changes inthe state rates of the aerodynamic vehicle is repeated for each controleffector in order to construct the entire matrix.

Alternatively, the matrix$\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack$

may be determined based upon an analytic calculation. According to thisalternative technique, a nonlinear multidimensional analytic curve maybe fit to each respective aerodynamic coefficient defined by theaerodynamic database. In this regard, the aerodynamic databaseseparately defines each aerodynamic coefficient at each of a largenumber of different flight conditions, with a respective flightcondition defined by a respective system state vector {overscore (x)}and the current state of the control effectors. The nonlinearmultidimensional curves may be fit to respective aerodynamiccoefficients according to any of a variety of techniques. In oneembodiment, however, the nonlinear multidimensional curves are fit torespective aerodynamic coefficients. Since the aerodynamic coefficientsare now represented by analytic functions, the partial derivatives ofeach aerodynamic coefficient with respect to a change in a respectivecontrol effector may then be readily determined by hand or, morecommonly, by utilizing a commercially available program such asMathematica. By utilizing the nonlinear multidimensional polynomialcurve representing each aerodynamic coefficient, along with dynamicpressure, vehicle mass, inertia, span, reference area and otherparameters, the force buildup equations for the aerodynamic vehicle mayagain be constructed as known to those skilled in the art. The partialderivatives of each force with respect to each aerodynamic coefficientmay then be determined. By utilizing the chain rule and the partialderivatives of the aerodynamic coefficients with respect to changes inrespective control effectors and the partial derivatives of the forceswith respect to respective aerodynamic coefficients, the partialderivatives of the forces with respect to changes in respective controleffectors may be determined. By factoring out the mass and inertia ofthe aerodynamic vehicle, the partial derivatives of the forces withrespect to changes in respective control effectors can be translatedinto the partial derivatives of the state rates of the aerodynamicvehicle with respect to changes in each control effector. Thereafter,the matrix can be constructed as described above.

Regardless of the manner in which the matrix$\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack$

is to be constructed, the matrix is preferably determined in real timebased upon the current flight conditions including the dynamic pressureand the current control effector commands {overscore (δ)} of theaerodynamic vehicle. Following construction of the matrix, theanticipated change in each state rate of the aerodynamic vehicle isdetermined by the vector multiplication of the vector {overscore (δ)}representing the current commands and the matrix. In particular, the dotproduct of the vector representing the current commands and the matrixis determined.

By taking into account the current flight conditions including, forexample, the dynamic pressure and, in turn, the velocity of theaerodynamic vehicle during the construction of the matrix, theanticipated change in the plurality of state rates is based not onlyupon the current commanded state of the control effectors, but also thecurrent flight conditions. In this regard, the matrix is constructedsuch that the anticipated change in each state rate is dominated atthose phases of flight, such as vertical takeoff and landing, in whichthe aerodynamic vehicle has low or no velocity by the thrust variationsand the nozzle vectoring with little if any, contribution by theaerodynamic surfaces. As the velocity increases, the contributionprovided by the aerodynamic surfaces to the anticipated change in eachstate rate correspondingly increases while the contribution provided bythrust variations and nozzle vectoring remains unchanged until thecontributions provided by the aerodynamic surfaces are of sufficientmagnitude to control the anticipated changes in each state rate athigher velocities without the aid of propulsive devices, such as thrustvariations and nozzle vectoring. The increasing dynamic pressure haslittle affect on the amount of control authority generated by propulsivedevices. So, as dynamic pressure increases, the amount of augmenationrequired by the use of the propulsive devices decreases until theaerodynamic surfaces provide all the required authority and thepropulsive devices can be turned off to conserve fuel or used toincrease airspeed. Generally, aerodynamic surfaces are a much moreefficient way to control the air vehicle when compared to propulsivedevices.

The desired change {overscore ({dot over (x)})}_(com) in the respectivestate rates of the aerodynamic vehicle is also provided, such as bypilot input, and is stored by a conventional sample and hold circuit 11.This desired change {overscore ({dot over (x)})}_(com) in the respectivestate rates of the aerodynamic vehicle may represent a change in thestate rates of selected states of the aerodynamic vehicle or all of thestates of the aerodynamic vehicle, typically depending upon the pilotinput. In order to determine the manner in which the control effectorsmust be controlled in order to affect the desired change {overscore({dot over (x)})}_(com) in the respective state rates of the aerodynamicvehicle, the difference between the anticipated and desired changes inthe state rates of the aerodynamic vehicle is determined. Since thedesired change {overscore ({dot over (x)})}_(com) in the respectivestate rates of the aerodynamic vehicle is also typically represented bya vector, the vector difference between the dot product representing theanticipated change in state rates of the aerodynamic vehicle and thevector representing the desired changes in the state rates is obtainedas shown in block 12 of FIG. 1.

According to one advantageous aspect of the present invention, thedifference between the anticipated and desired changes in the staterates of the aerodynamic vehicle may be weighted based upon a predefinedcriteria. One predefined criteria defines the relative importance of therespective states of the aerodynamic vehicle. Thus, the differencesbetween the anticipated and desired changes in the state rates of theaerodynamic vehicle, typically represented as a vector difference, canbe weighted so as to affect changes in some states of the aerodynamicvehicle more rapidly than other states due to the relative importance ofthe states for which changes are more rapidly affected. As such, arespective weight {overscore (w)} may be assigned to the state of theaerodynamic vehicle, such as during system configuration or the like.

Another predetermined criteria is a predefined penalty {overscore (p)}that may serve to place lesser or greater emphasis on outlier values. Inthis regard, the effect of the predefined penalty will vary based uponthe magnitude of the difference between the anticipated and desiredchanges in the respective state rate of the aerodynamic vehicle, withrelative large differences being considered outliers. For example, smallpenalties may be assigned to the outliers in those systems that aredesigned to factor the impact of the outliers into the control process,while large penalties may be assigned to outliers in those systems thatdesire to deemphasize the contributions of outliers since they may beattributable to an error. By way of example, the control methoddesirably maintains the total area required by each engine. In thisregard, for a respective engine providing a certain level of thrust, theeffective outlet area that the engine sees must remain constant as thenozzles are opened, closed and repositioned.

In order to affect the weighting, the vector operator (designated 14 inFIG. 1) is defined as follows:

({overscore (ν)}, {overscore (w)}, {overscore (p)})_(i) =w_(i)sgn(ν_(i))∥ν_(i)∥^(p) ^(_(i)) ⁻¹

wherein i represents a respective state of the aerodynamic vehicle,w_(i) is the weight assigned to each state of the aerodynamic vehicle,p_(i) is the predefined penalty assigned to each state of theaerodynamic vehicle and v_(i) is the difference between the anticipatedand desired changes in each state rate of the aerodynamic vehicle. Bothw_(i) and p_(i) are defined to be greater than or equal to 0. Bymultiplying the vector difference between the anticipated and desiredchanges in the state rates of the aerodynamic vehicle and the vectoroperator as shown in block 14, the weighted differences between theanticipated and desired changes in the state rates of the aerodynamicvehicle are obtained.

These weighted differences between the anticipated and desired changesin the state rates of the aerodynamic vehicle are then converted to thecorresponding changes in the control effectors to bring about thedesired changes {overscore ({dot over (x)})}_(com) in the state rates.In the illustrated embodiment, the weighted differences are multipliedby the transpose$\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack^{T}$

of the matrix representing the changes in the state rates of theaerodynamic vehicle in response to the changes in the plurality ofcontrol effectors as shown in block 16 of FIG. 1. In other words, thedot product of the weighted vector difference and the transpose of thematrix representing changes in the state rates of the aerodynamicvehicle in response to changes in the plurality of control effectors isdetermined. As such, the rate of changes {overscore ({dot over (δ)})} ofthe control effectors required to affect the desired changes in thestate rates of the aerodynamic vehicle subject to the anticipatedchanges in the state rates of the aerodynamic vehicle based upon thecurrent commanded state of each control effector is determined. Sinceeach term of the vector difference between the anticipated and desiredchanges in the state rates of the aerodynamic vehicle has been weighted,the resulting commands to the control effectors to affect the desiredchange in the state rates of the aerodynamic vehicle are computed basedupon the predetermined criteria, such as the relative importance of therespective states of the aerodynamic vehicle and/or the weighting to begiven to any outlier measurements. By multiplying the weighteddifferences by the transpose of the matrix representing changes in thestate rates of the aerodynamic vehicle in response to changes in thecontrol effectors, the control method employs a gradient descenttechnique so as to cause the control effectors that will have thegreatest impact upon effecting the desired change to be adjusted morethan the control effectors that would have less impact upon effectingthe desired change, thereby improving the efficiency of the controlscheme by using all available effectors in a coordinated fashion.

The rate of changes {overscore ({dot over (δ)})} of the controleffectors required to affect the desired changes in the state rates ofthe aerodynamic vehicle may also be weighted by a gain matrix as shownby block 17 based upon the relative or perceived importance of therespective control effectors. The gain matrix K_(ij) is a diagonal,positive, semi-definite matrix with one term of the gain matrixassociated with the rate of change of each respective control effector.Typically the values of the gain matrix are selected in advance withvalues larger than one serving to increase the rate of change of therespective control effector and values less than one serving to decreasethe rate of change of the respective control effector.

Since control effectors are typically subject to at least somelimitations, such as limitations in the predefined range of the controleffector and limitations in the permissible rate of change of thecontrol effector, the method and computer program product of oneadvantageous aspect of the present invention limit the permissiblechange of each control effector that has these predefined limitationssuch that the resulting commands issued to the control effectors do notattempt to exceed the limitations of the control effectors. Differentlimitations may be imposed upon different control effectors. Forexample, the control signals otherwise provided to the control effectorsmay be limited, such as by a vector limiter as shown in block 18 of FIG.1, to prevent the respective control effector from being commanded tochange at a rate that exceeds a predefined limit. In this regard, upperand/or lower limits may be predefined such that the permissible rate ofchange of the respective control effector must remain within theacceptable range bounded by the limit(s). However, in instances in whichthe aerodynamic vehicle includes a failure detection system, the upperand lower limits may be set to the position of the effector or effectorswhich are indicated as failed to maintain available performance in thisdegraded mode of operation.

In order to convert the rates of change {overscore ({dot over (δ)})} ofthe control effectors that have been determined to create the desiredchange in the state rates and, in turn, the state of the aerodynamicvehicle into control effector commands, the rates of change areintegrated as represented by block 20 of FIG. 1. In this regard, therates of change are integrated by employing a local feedback loop inwhich a time delay 22 and a limiter 24 are located in the feedforwardpath. The limiter serves to maintain each control effector within apredefined range. For example, the position of a nozzle or controlsurface may be limited so as to remain within a predefined range ofpositions, also typically defined by predefined upper and/or lowerlimits.

Once the desired changes in the control effectors have beenappropriately limited so as to prevent any control effector from beingcommanded to exceed its predefined limitations, the changes in eachcontrol effector that have been determined to affect the desired changein the state rates of the aerodynamic vehicle are issued as commands toeach of the control effectors and, in the illustrated embodiment, arestored by the zero order hold 26. As such, the desired change in thestate rates and, in turn, the desired change in the time rate of changeof the system state vector of the aerodynamic vehicle will be affected.

By weighting the differences between the anticipated and desired changesin the state rates of the aerodynamic vehicle, the method of the presentinvention effectively affects the desired change in the plurality ofstates of the aerodynamic vehicle in a manner which minimizes theassociated costs, as defined by the weighting. In this regard, the costof the change in the plurality of states of the aerodynamic vehicle isdefined as follows:${{cost}\left( {\overset{\_}{\delta},\overset{\_}{w},\overset{\_}{p}} \right)} = {\left( {\sum\limits_{i = 1}^{n}\quad {w_{i}\frac{1}{p_{i}}{{sgn}\left( {{\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack \overset{\_}{\delta}} - {\overset{\overset{.}{\_}}{x}}_{com}} \right)}{{{\left\lbrack \frac{\partial\overset{\overset{.}{\_}}{x}}{\partial\overset{\_}{\delta}} \right\rbrack \overset{\_}{\delta}} - {\overset{\overset{.}{\_}}{x}}_{com}}}^{p_{i}}}} \right).}$

As described above, this cost is minimized even in instances in whichone or more of the control effectors failed or are otherwise defectiveor frozen in position by design. In this regard, the control method isrobust to failures of one or more control effectors since the remainingcontrol effectors are forced or commanded in the direction to bringabout the desired change while minimizing the resulting costs. Since thecontinued use of the failed control effectors will come at a large costdue to the predefined penalty p_(i) assigned to outliers, theminimization of the cost will cause the other functional controleffectors to be recruited and repositioned to affect the desired change.

By minimizing the resulting cost of affecting the desired changes in thestate rates of the aerodynamic vehicle, the control method of thepresent invention affects the desired changes in an efficient manner.See copending U.S. patent application Ser. Nos. 09/967,403 and09/967,446 for further discussion of the cost function. The entirecontents of each of these applications is incorporated herein byreference.

Based upon the cost function, the affect of the predefined penalty p_(i)that permits greater or lesser emphasis to be placed upon outliers,i.e., large differences between the anticipated and desired changes inthe state rates, can be illustrated. In this regard, FIGS. 2 and 3 aretwo different graphical illustrations of the same curves representingthe relationship between the cost and difference v between theanticipated and desired change in a respective state rate of anaerodynamic vehicle. As indicated, larger values of p, i.e., p>2, imposegreater penalties upon outliers, thereby increasing the overall cost.Conversely, smaller values of p, i.e., 1<p<2, permit outliers tocontinue to contribute to the cost, thereby decreasing the cost. Thus,the control of the control effectors may be tailored by a systemdesigner or the like based upon the manner in which outliers which maybe representative of an error or failure in the system are to be treatedby either being excluded from the control system or by continuing to beincluded, either completely or in some partial degree. In addition, thecontrol of the control effectors may be further tailored as describedabove by establishing another weighting w based upon the relativeimportance of the respective states of the aerodynamic vehicle.

Furthermore, both the continuous and discrete modes of the controlmethod converge. Proof of this convergence is provided by copending U.S.patent application Ser. Nos. 09/967,403 and 09/967,446. Moreover, thecontrol method is capable of quickly determining and then repeatedlyredetermining the command to be issued to the control effector so as toinsure that vehicle stability is maintained. While the control methodwas designed to be rapid, embodiments of the control method may utilizesingle precision floating point numerical representations of the variousquantities in order to obtain accurate commands while further increasingthe computational throughput.

As indicated above, the method of controlling the plurality of controleffectors of an aerodynamic vehicle may be embodied by a computerprogram product that directs the operation of a flight control computeror the like to issue the commands to the plurality of control effectorsin order to affect the desired changes. In this regard, the computerprogram product includes a computer-readable storage medium, such as thenon-volatile storage medium, and computer-readable program codeportions, such as a series of computer instructions, embodied in thecomputer-readable storage medium. Typically, the computer program isstored by a memory device and executed by an associated processing unit,such as the flight control computer or the like.

In this regard, FIG. 1 is a block diagram, flowchart and control flowillustration of methods and program products according to the invention.It will be understood that each block or step of the block diagram,flowchart and control flow illustrations, and combinations of blocks inthe block diagram, flowchart and control flow illustrations, can beimplemented by computer program instructions. These computer programinstructions may be loaded onto a computer or other programmableapparatus to produce a machine, such that the instructions which executeon the computer or other programmable apparatus create means forimplementing the functions specified in the block diagram, flowchart orcontrol flow block(s) or step(s). These computer program instructionsmay also be stored in a computer-readable memory that can direct acomputer or other programmable apparatus to function in a particularmanner, such that the instructions stored in the computer-readablememory produce an article of manufacture including instruction meanswhich implement the function specified in the block diagram, flowchartor control flow block(s) or step(s). The computer program instructionsmay also be loaded onto a computer or other programmable apparatus tocause a series of operational steps to be performed on the computer orother programmable apparatus to produce a computer implemented processsuch that the instructions which execute on the computer or otherprogrammable apparatus provide steps for implementing the functionsspecified in the block diagram, flowchart or control flow block(s) orstep(s).

Accordingly, blocks or steps of the block diagram, flowchart or controlflow illustrations support combinations of means for performing thespecified functions, combinations of steps for performing the specifiedfunctions and program instruction means for performing the specifiedfunctions. It will also be understood that each block or step of theblock diagram, flowchart or control flow illustrations, and combinationsof blocks or steps in the block diagram, flowchart or control flowillustrations, can be implemented by special purpose hardware-basedcomputer systems which perform the specified functions or steps, orcombinations of special purpose hardware and computer instructions.

Many modifications and other embodiments of the invention will come tomind to one skilled in the art to which this invention pertains havingthe benefit of the teachings presented in the foregoing descriptions andthe associated drawings. Therefore, it is to be understood that theinvention is not to be limited to the specific embodiments disclosed andthat modifications and other embodiments are intended to be includedwithin the scope of the appended claims. Although specific terms areemployed herein, they are used in a generic and descriptive sense onlyand not for purposes of limitation.

What is claimed is:
 1. An integrated method of controlling a pluralityof control effectors of an aerodynamic vehicle having a plurality ofstates, the method comprising: determining a current commanded state ofthe plurality of control effectors including the current commandedstates of nozzle vectoring and at least one aerodynamic surface;determining the anticipated changes in the plurality of states basedupon the current commanded state of each control effector and currentflight conditions; determining differences between anticipated changesin the plurality of states of the aerodynamic vehicle based upon thecurrent commanded state of the plurality of control effectors anddesired changes in the plurality of states of the aerodynamic vehicle;and controlling the plurality of control effectors at least partiallybased upon the differences in order to implement at least a portion ofthe desired changes in the plurality of states of the aerodynamicvehicle.
 2. An integrated method according to claim 1 whereincontrolling the plurality of control effectors comprises adjusting acontrol effector that effects a greater portion of the desired changemore than a control effector that effects a smaller portion of thedesired change.
 3. An integrated method according to claim 1 furthercomprising limiting the permissible change of at least one of thecontrol effectors, wherein controlling the plurality of controleffectors comprises controlling the plurality of control effectors basedupon the weighted differences subject to limitations in the permissiblechanges of at least one of the control effectors in order to implementat least a portion of the desired change in the plurality of states ofthe aerodynamic vehicle without exceeding the permissible changes of atleast one of the control effectors.
 4. An integrated method according toclaim 3 wherein limiting the permissible changes of at least one of thecontrol effectors comprises limiting the permissible rate of change ofat least one of the control effectors.
 5. An integrated method accordingto claim 3 wherein limiting the permissible changes of at least one ofthe control effectors comprises limiting at least one of the controleffectors to within a predefined range.
 6. An integrated method ofcontrolling a plurality of control effectors of an aerodynamic vehiclehaving a plurality of states, the method comprising: determining acurrent commanded state of the plurality of control effectors includingthe current commanded states of nozzle vectoring and at least oneaerodynamic surface; determining differences between anticipated changesin the plurality of states of the aerodynamic vehicle based upon thecurrent commanded state of the plurality of control effectors anddesired changes in the plurality of states of the aerodynamic vehicle;weighting the differences between the anticipated and desired changesbased upon a predetermined criteria, and controlling the plurality ofcontrol effectors at least partially based upon the differences in orderto implement at least a portion of the desired changes in the pluralityof states of the aerodynamic vehicle, wherein controlling the pluralityof control effectors is at least partially based upon the weighteddifferences.
 7. An integrated method according to claim 6 whereinweighting the differences comprises weighting the differences based uponthe relative importance of the respective states of the aerodynamicvehicle.
 8. An integrated method according to claim 6 wherein weightingthe differences comprises weighting the differences based upon apredefined penalty having an effect that varies based upon the magnitudeof a respective difference.
 9. An integrated method of controlling aplurality of control effectors of an aerodynamic vehicle having aplurality of states, the method comprising: determining a currentcommanded state of the plurality of control effectors including thecurrent commanded states of nozzle vectoring and at least oneaerodynamic surface; determining differences between anticipated changesin the plurality of states of the aerodynamic vehicle based upon thecurrent commanded state of the plurality of control effectors anddesired changes in the plurality of states of the aerodynamic vehicle,wherein determining the differences between the anticipated and desiredchanges in the plurality of states of the aerodynamic vehicle comprises:determining a first dot product of a vector representing the currentcommanded state of each control effectors and a matrix representingchanges in the plurality of state rates of the aerodynamic vehicle inresponse to changes in the plurality of control effector, wherein thematrix is comprised of a plurality of terms, each term representing theanticipated change in a respective state rate of the aerodynamic vehiclein response to the change of a respective control effector; andobtaining a vector difference between the first dot product and a vectorrepresenting the desired change in the plurality of states of theaerodynamic vehicle; and controlling the plurality of control effectorsat least partially based upon the differences in order to implement atleast a portion of the desired changes in the plurality of states of theaerodynamic vehicle.
 10. An integrated method according to claim 9further comprising constructing the matrix to represent changes in thestate rates associated with lift, attitude and a plurality of engineparameters of the aerodynamic vehicle in response to changes in theplurality of control effectors.
 11. An integrated method according toclaim 9 further comprising determining a second dot product of theweighted vector difference and a transpose of the matrix representingchanges in the plurality of state rates of the aerodynamic vehicle inresponse to changes in the plurality of control effectors, and whereincontrolling the plurality of control effectors is at least partiallybased upon the second dot product.
 12. An integrated method according toclaim 11 further comprising weighting the second dot product based uponthe relative importance of the respective control effectors such thatthe plurality of control effectors are controlled based, at leastpartially, upon the weighted second dot product.
 13. An integratedmethod of controlling a plurality of control effectors of an aerodynamicvehicle having a plurality of states, the method comprising: determininga current commanded state of a plurality of control effectors includingthe current commanded state of at least one aerodynamic surface and atleast one control effector selected from the group consisting of thrustvariations and nozzle vectoring; determining differences betweenanticipated changes in the plurality of states of the aerodynamicvehicle based upon the current commanded state of the plurality ofcontrol effectors and desired changes in the plurality of states of theaerodynamic vehicle; weighting the differences based upon at least oneof the relative importance of the respective states of the aerodynamicvehicle and a predefined penalty having an effect that varies based uponthe magnitude of a respective difference; and controlling the pluralityof control effectors at least partially based upon the weighteddifferences in order to implement at least a portion of the desiredchanges in the plurality of states of the aerodynamic vehicle.
 14. Anintegrated method according to claim 13 wherein determining thedifferences between the anticipated and desired changes in the pluralityof states of the aerodynamic vehicle comprises determining theanticipated changes in the plurality of states based upon the currentcommanded state of each control effector and current flight conditions.15. An integrated method according to claim 13 wherein controlling theplurality of control effectors comprises adjusting a control effectorthat effects a greater portion of the desired change more than a controleffector that effects a smaller portion of the desired change.
 16. Anintegrated method according to claim 13 further comprising limiting thepermissible change of at least one of the control effectors, whereincontrolling the plurality of control effectors comprises controlling theplurality of control effectors based upon the weighted differencessubject to limitations in the permissible changes of at least one of thecontrol effectors in order to implement at least a portion of thedesired change in the plurality of states of the aerodynamic vehiclewithout exceeding the permissible changes of at least one of the controleffectors.
 17. An integrated method according to claim 16 whereinlimiting the permissible changes of at least one of the controleffectors comprises limiting the permissible rate of change of at leastone of the control effectors.
 18. An integrated method according toclaim 16 wherein limiting the permissible changes of at least one of thecontrol effectors comprises limiting at least one of the controleffectors to within a predefined range.
 19. An integrated methodaccording to claim 13 wherein determining the differences between theanticipated and desired changes in the plurality of states of theaerodynamic vehicle comprises: determining a first dot product of avector representing the current commanded state of each controleffectors and a matrix representing changes in the plurality of staterates of the aerodynamic vehicle in response to changes in the pluralityof control effector, wherein the matrix is comprised of a plurality ofterms, each term representing the anticipated change in a respectivestate rate of the aerodynamic vehicle in response to the change of arespective control effector; and obtaining a vector difference betweenthe first dot product and a vector representing the desired change inthe plurality of states of the aerodynamic vehicle, and whereinweighting the differences comprises weighting the vector difference. 20.An integrated method according to claim 19 further comprisingconstructing the matrix to represent changes in the state ratesassociated with lift, attitude and a plurality of engine parameters ofthe aerodynamic vehicle in response to changes in the plurality ofcontrol effectors.
 21. An integrated method according to claim 19further comprising determining a second dot product of the weightedvector difference and a transpose of the matrix representing changes inthe plurality of state rates of the aerodynamic vehicle in response tochanges in the plurality of control effectors, and wherein controllingthe plurality of control effectors is at least partially based upon thesecond dot product.
 22. An integrated method according to claim 19further comprising weighting the second dot product based upon therelative importance of the respective control effectors such that theplurality of control effectors are controlled based, at least partially,upon the weighted second dot product.
 23. An integrated method ofcontrolling a plurality of control effectors of an aerodynamic vehiclehaving a plurality of states, the method comprising: determining acurrent commanded state of a plurality of control effectors includingthe current commanded state of at least one aerodynamic surface and atleast one control effector selected from the group consisting of thrustvariations and nozzle vectoring; determining differences betweenanticipated changes in the plurality of states of the aerodynamicvehicle based upon the current commanded state of each of the pluralityof control effectors and desired changes in the plurality of states ofthe aerodynamic vehicle; limiting the permissible change of at least oneof the control effectors; and controlling the plurality of controleffectors at least partially based upon differences between theanticipated and desired changes in the plurality of states of theaerodynamic vehicle subject to limitations in the permissible changes ofat least one of the control effectors in order to implement at least aportion of the desired change in the plurality of states of theaerodynamic vehicle without exceeding the permissible changes of atleast one of the control effectors.
 24. An integrated method accordingto claim 23 wherein determining the differences between the anticipatedand desired changes in the plurality of states of the aerodynamicvehicle comprises determining the anticipated changes in the pluralityof states based upon the current commanded state of each controleffector and current flight conditions.
 25. An integrated methodaccording to claim 23 wherein controlling the plurality of controleffectors comprises adjusting a control effector that effects a greaterportion of the desired change more than a control effector that effectsa smaller portion of the desired change.
 26. An integrated methodaccording to claim 23 wherein limiting the permissible changes of atleast one of the control effectors comprises limiting the permissiblerate of change of at least one of the control effectors.
 27. Anintegrated method according to claim 23 wherein limiting the permissiblechanges of at least one of the control effectors comprises limiting atleast one of the control effectors to within a predefined range.
 28. Anintegrated method according to claim 23 further comprising weighting thedifferences between the anticipated and desired changes based upon apredetermined criteria, and wherein controlling the plurality of controleffectors is at least partially based upon the weighted differences. 29.An integrated method according to claim 28 wherein weighting thedifferences comprises weighting the differences based upon the relativeimportance of the respective states of the aerodynamic vehicle.
 30. Anintegrated method according to claim 28 wherein weighting thedifferences comprises weighting the differences based upon a predefinedpenalty having an effect that varies based upon the magnitude of arespective difference.
 31. An integrated method according to claim 23wherein determining the differences between the anticipated and desiredchanges in the plurality of states of the aerodynamic vehicle comprises:determining a first dot product of a vector representing the currentcommanded state of each of the plurality of control effectors and amatrix representing changes in the plurality of state rates of theaerodynamic vehicle in response to changes in the plurality of controleffectors, wherein the matrix is comprised of a plurality of terms, eachterm representing the anticipated change in a respective state rate ofthe aerodynamic vehicle in response to the change of a respectivecontrol effector; and obtaining a vector difference between the firstdot product and a vector representing the desired change in theplurality of states of the aerodynamic vehicle.
 32. An integrated methodaccording to claims 31 further comprising constructing the matrix torepresent changes in the state rates associated with lift, attitude anda plurality of engine parameters of the aerodynamic vehicle in responseto changes in the plurality of control effectors.
 33. An integratedmethod according to claim 31 further comprising determining a second dotproduct of a representation of the vector difference and a transpose ofthe matrix representing changes in the plurality of state rates of theaerodynamic vehicle in response to changes in the plurality of controleffectors, and wherein controlling the plurality of control effectors isat least partially based upon the second dot product.
 34. An integratedmethod according to claim 31 further comprising weighting the second dotproduct based upon the relative importance of the respective controleffectors such that the plurality of control effectors are controlledbased, at least partially, upon the weighted second dot product.